Dental-amalgam mixer.



: 1,173,519. Patented Feb. 29, 1916.

W. UGHES.

DENTA LGAM MIXER.

N FILED M{AY1B,1915

APPLICATIO UNTTE AT DENTAL-AMALGAM IWIXER.

Specification of Letters Patent.

Patented Feb. 29, 1916.

Application filed May 18, 1915. Serial No. 28,901.

To aZZ whom it may concern:

Be it known that I, lVILLIAM G. HUGHEs, a citizen of the United States,residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inDental-Amalgam Mixers, of which the following a specification.

This invention relates to certain new and useful improvements in dentalamalgam mixers.

The primary object of this invention is to provide a device especiallyadapted for dental use for mixing amalgam for teeth fillings, andwhereby a greater edge strength is produced with a slight saving ofmercury, a. complete control of the setting properties of the amalgambeing also provided.

A further object is to provide a mixer operable by the usual dentalengine and whereby the alloy and mercury are rapidly and accuratelymixed to the proper filling consistency, the ingredients being rolledeither toward a common center, or outwardly as desired.

A still further object of the invention is to provide a mixing toolrevolved in either direction by insertion within the chuck of a dentalengine and capable of mixing amalgam for silver fillings and capable ofimparting different mixing movements to the ingredients by a groovedarrangement of the tool and the directionin which the same is actuated.

lVith these general objects in view and others that will. appear as thenature of the invention is better understood, the same consists in thenovel combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings, and pointedout inthe appended claims.

In the drawings forming a part of this application and in whichlike-designating characters refer to corresponding parts throughout theseveral views, Figure 1 is a side elevation of the operative connectionsof a dental engine illustrated in use in connection with the presentdevice, the cup or mortar thereof being shown in central verticalsection. Fig. 2 is a top plan View of the mixing tool or pestle employedwith the-device, and Figs. 8 and 4 are partial radial sectional viewstaken upon lines III-III and IVIV respectively of Fig. 2.

Referring more in detail to the drawings,

the device is best illustrated in Fig. 1 operatively positioned inconnection with a hand piece 10 of a dental engine of the usualconstruction and having the usual wrist piece 11 and chuck adjustment12.

A mortar or cup 13 is provided within which the ingredients are adaptedto be mixed for forming the amalgam, the said cup being in the form of acylindrical member preferably formed of metal and having a receivingchamber 14 milled out of its upper face 1.5 thereof, the said chamberhaving a substantially semi-spherical inner end or bottom 16.

The pestle or mixing tool consists of a spherical member or ball 17preferably formed of metal and having a radially arranged shank or stem18 projecting therefrom and adapted to be received and retained withinthe engine chuck in the outer end portion 19 of the hand piece 10.

The diameter of the ball 17 is such as to allow the ball to closely fitwithin the bottom 16 of the chamber 14c and to operatively engage thealloy which is placed in the cup and to mix the same with the mercurywhich is added thereto during the rotation of the ball by the dentalengine.

The ball 17 is provided upon its face opposite the stem 18 withoppositely positioned communicating curved grooves 20 tapering towardtheir diametrically opposite free ends 21. The said grooves 20 are eachsubstantially crescent-shaped and when taken together are substantiallyS-shaped, while the cutting of the grooves within the spherical body ofthe pestle 17 forms slightly sharpened inner curved edges 22 whichassist in pulverizing and mixing the ingredients as the pestle revolvesin a scouring movement within the receiving chamber bottom 16 whichsemi-spherically conforms to the shape of the pestle. The provision ofthe curved cutting edges is a distinctive feature of the improvement,said edges coacting with the smooth semi-spherical bottom of the mortarto insure a thorough pulveri- Zation and admixing of the ingredientsused. During the operative rotation of the pestle ball 17 in a directionfrom left to right, the amalgam ingredients will be rolled from theouter circumference toward the center, while a reverse rotation of theball will roll the ingredients outwardly and in this manner a completeand thorough mixing is accomplished. The proper consistency for, thesilver filling is derived in the usual manner by regulating the amountof mercury added to the mortar, although less mercury is required inView of the added efliciency in mixing the same, the setting of theamalgam being controlled by regulating the speed of the mixingoperation. The flaring sides of the chamber 14 allows the hand piece 10and pestle shank 18 to be given desirable gyratory movements during theoperative rotation of the ball pestle.

It will be understood that any operating means may be provided forimparting the necessary revolutions to the ball pestle as well asemploying dilferent forms of receiving mortar therefor Without departingfrom the spirit and scope of the invention as claimed, while minordetails of construction may be likewise changed.

Vfhat I claim as new is':

1. A spherical head for rotary pestles having on its undermortar-engaging surface a plurality of arcuate grooves having theircenters eccentric in plan to the vertical axis of the pestle and meetingcentrally of the bottom plan of the head.

2. A spherical head for rotary pestles having on its undermortar-engaging surface a plurality of arcuate grooves having theircenters eccentric in plan to the vertical axis of the pestle and meetingcentrally of the bottom plan of the head, said grooves broadening fromtheir outer extremities to their meeting plane.

3. The combination with a mortar having a material receiving recess ofinverted frusto-conoidal form and having a hemispherical extensionforming its bottom, and a grinding sphere having its lower hemispherelocated in the hemispherical extension and provided with a mill dress.

4. The combination with a mortar having' a material receiving recess ofinverted frusto-conoidal form and having a hemispherical extensionforming itsv bottom, and

a grinding sphere having its lower hemi-,

sphere located in the hemispherical extension and provided with a milldress, the outer portions of the mill dress terminating just below the,upper part of the hemisphere and the, center of the dress forming agathering chamber.

In testimony whereof I affix my signature.

WILLIAM G. HUGHES.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

